The present invention is directed to a vehicle frame and, more particularly, to a bicycle, tricycle or motorcycle frame capable of storing compressed gas inside the frame members thereof.
Vehicles driven by human power, such as bicycles, motor-assisted bicycles, and tricycles, have a frame and wheels that are rotatably supported by the frame and are mounted with air-filled rubber tires. In the case of a bicycle or motor-assisted bicycle, the frame usually comprises tubes made of metal or synthetic resin, and a space is formed on the inside of the frame. With a bicycle, for instance, a shift apparatus, a brake apparatus, or the like can be operated by using a pneumatic device that is lightweight and easy to operate. Of course, such devices usually require a compressed air source to operate them. In the case of a vehicle that is large and has a motor, such as an automobile, an air compressor can be mounted on board, but the installation of such a large compressed air source is a difficult proposition with a vehicle that is small, lightweight, and human-powered, such as a bicycle. When an gas actuated devices are used with a bicycle, it is possible to mount a small gas cylinder filled with liquefied gas, for example, on the bicycle. With bicycles that need to be lightweight, however, the installation of a small gas cylinder is a problem in that the weight of the cylinder makes the bicycle that much heavier. Light weight is a concern common to all vehicles driven by human power, and not just bicycles, and reducing the weight allows the running performance of the vehicle to be enhanced. Even if weight were not a problem, however, another problem with the use of a gas cylinder that has been charged with carbon dioxide or another liquefied gas as the compressed gas source is the difficulty of recharging the gas cylinder with gas when it runs out. This means that expensive gas cylinders have to be kept on hand at all times.